The invention relates to a latent heat accumulator comprising a vessel for receiving a latent heat storage medium and a circuit for a heat exchanger medium, this being immiscible with the latent heat storage medium, having a different density to the heat storage medium and being openly conveyed through the storage medium, a collecting chamber being provided in the vessel for the heat exchanger medium, a heat exchanger being disposed in this collecting chamber, an external heat carrier medium flowing through this heat exchanger, which brings about a transfer of heat between heat carrier medium and heat exchanger medium.